Oh...I noticed a slower increase of phosphates over the next several weeks. It wasn't overly dramatic. I could have just replaced phosguard every two weeks. That would be 3-4 times compared to one bag of Chemipure for 7-8 weeks. But did I replace phosguard every two weeks like clockwork? I did not - get lazy, busy and such. That's why I pay for convenience. It's not really a performance issue.
Also, just so you have the whole picture, my phosphate still climbs from .03 to about .20 ppm over 7-8 weeks (instead of 3-4 weeks with phosguard and my laziness). When it gets up to .2 ppm I use lanthanum chloride (about 10 drops) and knock it back down to .03, replace my Chemipure and off and running again for the next two months.